NAPHTHALENE. 393 



Tetrachlornaphthalene, C'H 4 C1 4 . Colorless nee- 

 dles ; fusing point, 130. 



Enneachlordinaphthalene, C 20 H 7 C1 9 . The end- 

 product of the action of chlorine on heated chlorinated 

 naphthalene. White, delicate needles; fusing point, 

 156-158. 



Pentachlornaphthalene, C IO H 3 C1 5 . Is formed by 

 the action of phosphorus chloride on dichlornaphtho- 

 quinone and chloroxjnaphthalenic acid. Colorless nee- 

 dles ; fusing point, 168.5. 



Perchlornaphthalene, C 10 C1 8 . Prisms ; fusing 

 point, 135. 



Naphthalene yields substitution-products with bro- 

 mine, but does not combine directly with it. Mono- 

 bromnaphthalene, C 10 H 7 Br. Colorless liquid; boiling 

 point, Zll . .-Dibromnaphthalene, C^IPBr 2 . Long 

 needles of a silky lustre; fusing point, 81. $-Dibrom- 

 naphthalene, C 10 H 6 Br 2 , is formed together with the 

 a-compound when bromine acts upon a-sulphonaphtha- 

 lic acid. Needles; fusing point, 126-127. Tribrom- 

 naphthalene, C 10 H 5 Br 3 . Colorless needles ; fusing point, 

 75. Tetrabromnaphthalene, C 10 H 4 Br 4 . Colorless prisms, 

 but slightly soluble in alcohol. Pentabromnaphthalene, 

 C 10 H 3 Br 5 . Colorless granular crystals, insoluble in 

 alcohol. 



a-Cyannaphthalene, C 10 H 7 .CN, is formed by the 

 distillation of a mixture of potassium a-sulpho- 

 naphthalate with potassium cyanide. Is also formed 

 when naphthylamine oxalate is distilled, and the distil- 

 late, which contains a great deal of naphthylformamide, 

 heated with concentrated hydrochloric acid. Color- 

 less, broad needles; insoluble in water, easily soluble 

 in alcohol*. Fuses at 37.5 ; has a strong tendency to 

 remain liquid, and boils without undergoing decompo- 

 sition at 297-298. p-Cyannaphthalene, C 10 H 7 .CK Is 

 obtained in the same way from potassium j3-sulpho- 



